configure.ac: update directory space check

OMPI_CANONICALIZE_PATH broke on MacOS when `/usr/bin/python`
disappeared (in favor of `/usr/bin/python3`) in MacOS Monterrey.  Make
things simpler by not canonicalizing the path to begin with.

Specifically: just look at `pwd`, $srcdir, and $prefix.  Even if
$srcdir and/or $prefix are relative to the build dir, the union of all
the checks will ensure that none of the target paths will contain
spaces.

Signed-off-by: Jeff Squyres <jsquyres@cisco.com>

Author: jsquyres

configure.ac

@@ -128,29 +128,10 @@ AC_DEFUN([OMPI_CHECK_DIR_FOR_SPACES],[
            AC_MSG_ERROR([Cannot continue.])])
 ])
 
-AC_DEFUN([OMPI_CANONICALIZE_PATH],[
-    case $host_os in
-    darwin*)
-        # MacOS does not have "readlink -f" or realpath (at least as
-        # of MacOS Cataline / 10.15).  Instead, use Python, because we
-        # know MacOS comes with a /usr/bin/python that has
-        # os.path.realpath.
-        $2=`/usr/bin/python -c 'import os; print os.path.realpath("'$1'")'`
-        ;;
-    *)
-        $2=`readlink -f $1`
-        ;;
-    esac
-])
-
-OMPI_CHECK_DIR_FOR_SPACES([$srcdir], [a], [source tree])
-OMPI_CANONICALIZE_PATH([$srcdir], [ompi_dir])
-OMPI_CHECK_DIR_FOR_SPACES([$ompi_dir], [an], [absolute source tree])
-OMPI_CANONICALIZE_PATH([.], [ompi_dir])
+ompi_dir=`pwd`
 OMPI_CHECK_DIR_FOR_SPACES([$ompi_dir], [a], [build tree])
+OMPI_CHECK_DIR_FOR_SPACES([$srcdir], [a], [source tree])
 OMPI_CHECK_DIR_FOR_SPACES([$prefix], [a], [prefix])
-OMPI_CANONICALIZE_PATH([$prefix], [ompi_dir])
-OMPI_CHECK_DIR_FOR_SPACES([$ompi_dir], [an], [absolute prefix])
 
 opal_show_subtitle "Checking versions"