usnic: switch to use the new libfabric common library

The usnic BTL configure.m4 no longer needs to OPAL_CHECK_LIBFABRIC; it
just uses the results from opal/mca/common/libfabric's configure.m4.
We also now don't need to link against libfabric -- they just link
against the opal_common_libfabric library.

opal/mca/btl/usnic/Makefile.am

@@ -19,7 +19,7 @@
 # $HEADER$
 #
 
-AM_CPPFLAGS = -DBTL_IN_OPAL=1 $(opal_btl_usnic_CPPFLAGS)
+AM_CPPFLAGS = -DBTL_IN_OPAL=1 $(opal_common_libfabric_CPPFLAGS)
 
 EXTRA_DIST = README.txt README.test
 
@@ -91,12 +91,12 @@ mca_btl_usnic_la_SOURCES = $(component_sources)
 mca_btl_usnic_la_LDFLAGS = \
         $(opal_btl_usnic_LDFLAGS) \
         -module -avoid-version
-mca_btl_usnic_la_LIBADD = $(opal_btl_usnic_LIBS)
+mca_btl_usnic_la_LIBADD = \
+        $(OPAL_TOP_BUILDDIR)/opal/mca/common/libfabric/lib@OPAL_LIB_PREFIX@mca_common_libfabric.la
 
 noinst_LTLIBRARIES = $(lib)
 libmca_btl_usnic_la_SOURCES = $(lib_sources)
 libmca_btl_usnic_la_LDFLAGS = -module -avoid-version $(opal_btl_usnic_LDFLAGS)
-libmca_btl_usnic_la_LIBADD  =  $(opal_btl_usnic_LIBS)
 
 if OPAL_BTL_USNIC_BUILD_UNIT_TESTS
 usnic_btl_run_tests_CPPFLAGS = \

opal/mca/btl/usnic/configure.m4

@@ -94,15 +94,15 @@ AC_DEFUN([_OPAL_BTL_USNIC_DO_CONFIG],[
           ])
 
     # The usnic BTL requires libfabric support.
-    AS_IF([test "$opal_btl_usnic_happy" = "yes"],
-          [OPAL_CHECK_LIBFABRIC([opal_btl_usnic],
-              [opal_btl_usnic_happy=yes],
-              [opal_btl_usnic_happy=no])])
+    AS_IF([test "$opal_btl_usnic_happy" = "yes" && \
+           test "$opal_common_libfabric_happy" = "yes"],
+          [opal_btl_usnic_happy=yes],
+          [opal_btl_usnic_happy=no])
 
     # Make sure we can find the libfabric usnic extensions header
     AS_IF([test "$opal_btl_usnic_happy" = "yes" ],
           [opal_btl_usnic_CPPFLAGS_save=$CPPFLAGS
-           CPPFLAGS="$opal_btl_usnic_CPPFLAGS $CPPFLAGS"
+           CPPFLAGS="$opal_common_libfabric_CPPFLAGS $CPPFLAGS"
            AC_CHECK_HEADER([rdma/fi_ext_usnic.h],
                             [],
                             [opal_btl_usnic_happy=no])