libfabric: fix wrappers for static builds

Need to set the WRAPPER_EXTRA flags so that the wrappers for static
builds pull in -lfabric.

Also update/fix some comments.

(cherry picked from commit f135394)

Author: jsquyres

opal/mca/common/libfabric/configure.m4

@@ -5,25 +5,24 @@
 #                         of Tennessee Research Foundation.  All rights
 #                         reserved.
 # Copyright (c) 2015      Intel, Inc. All rights reserved.
+# Copyright (c) 2015 Cisco Systems, Inc.  All rights reserved.
 # $COPYRIGHT$
 #
 # Additional copyrights may follow
 #
 # $HEADER$
 #
 
-#
-# If LIBFABRIC support was requested, then build the LIBFABRIC support library.
-# This code checks just makes sure the check was done earlier by the
-# opal_check_libfabric.m4 code.
-#
-
 AC_DEFUN([MCA_opal_common_libfabric_CONFIG],[
     AC_CONFIG_FILES([opal/mca/common/libfabric/Makefile])
 
-    # check for libfabric request
+    # Check for libfabric.  Note that $opal_common_libfabric_happy is
+    # used in other configure.m4's to know if libfabric configured
+    # successfully.
     OPAL_CHECK_LIBFABRIC([opal_common_libfabric],
                          [opal_common_libfabric_happy=yes
+                          common_libfabric_WRAPPER_EXTRA_LDFLAGS=$opal_common_libfabric_LDFLAGS
+                          common_libfabric_WRAPPER_EXTRA_LIBS=$opal_common_libfabric_LIBS
                           $1],
                          [opal_common_libfabric_happy=no
                           $2])