check-exports: don't fail for diffs in libgstgl.def

The exported symbols will depend on the backends built
and be different from platform to platform. Should probably
be the win32 symbols anyway, which is not the case at the
moment. So for now just show any diff but not fail.

win32.mak

@@ -44,7 +44,10 @@ check-exports:
 	  if test "x$$libso" != "x"; then \
 	    echo Checking symbols in $$libso; \
 	    if ! ($(top_srcdir)/common/check-exports $$libdef $$libso) ; then \
-	      fail=1; \
+	      echo "$$libdef"; \
+	      if test "$$libbase" != "libgstgl"; then \
+	        fail=1; \
+	      fi; \
 	    fi; \
 	  fi; \
 	done ; \