configury: remove whitespace from "conftestval"-style tests

Several configure tests write integer result values to files and then
do something like foo=$(cat conftestval).  However, if the conftestval
file contains whitespace around the integer value (e.g., if
conftestval was written by a Fortran test code), then $foo will still
contain that whitespace, too -- which then propagates throughout the
configury and elsewhere.

This commit uses xargs to strip off the whitespace.  There's really
only one place where this is happening that is a problem, but let's do
it in all places where we foo=$(cat conftestval) with integer results,
just as a matter of consistency and defensive programming.

Thanks to Lisandro Dalcin for raising the issue.

Signed-off-by: Jeff Squyres <jeff@squyres.com>

Author: jsquyres

config/ompi_fortran_check_logical_array.m4

@@ -101,7 +101,7 @@ EOF
                  [ # assume we're ok
                   value=yes],
                  [OPAL_LOG_COMMAND([./conftest],
-                      [if test "`cat conftestval`" = "1" ; then
+                      [if test "`cat conftestval | xargs`" = "1" ; then
                            value=yes
                        else
                            value=no

config/ompi_fortran_check_real16_c_equiv.m4

@@ -141,7 +141,7 @@ EOF
              [AC_MSG_RESULT([Error!])
               AC_MSG_ERROR([Can not determine if REAL*16 bit-matches C if cross compiling])],
              [OPAL_LOG_COMMAND([./conftest],
-                 [fortran_real16_happy=`cat conftestval`],
+                 [fortran_real16_happy=`cat conftestval | xargs`],
                  [AC_MSG_RESULT([Error!])
                   AC_MSG_ERROR([Could not determine if REAL*16 bit-matches C type])
                  ])

config/ompi_fortran_get_alignment.m4

@@ -203,7 +203,7 @@ end program]])],
                           [AS_IF([test "$cross_compiling" = "yes"],
                                  [AC_MSG_ERROR([Can not determine common alignment when cross-compiling])],
                                  [OPAL_LOG_COMMAND([./conftest],
-                                                   [AS_VAR_SET(ompi_cv_fortran_common_alignment, [`cat conftestval`])],
+                                                   [AS_VAR_SET(ompi_cv_fortran_common_alignment, [`cat conftestval | xargs`])],
                                                    [AC_MSG_ERROR([Could not determine common alignment])])])],
 
                           [AC_MSG_WARN([Could not determine common alignment])

config/ompi_fortran_get_sizeof.m4

@@ -79,7 +79,7 @@ EOF
          AS_IF([test "$cross_compiling" = "yes"],
              [AC_MSG_ERROR([Can not determine size of $2 when cross-compiling])],
              [OPAL_LOG_COMMAND([./conftest],
-                 [AS_VAR_SET(type_var, [`cat conftestval`])],
+                 [AS_VAR_SET(type_var, [`cat conftestval | xargs`])],
                  [AC_MSG_ERROR([Could not determine size of $2])])])
 
         unset happy ompi_conftest_h