diff-merges: rename "combined_imply_patch" to "merges_imply_patch"

This is refactoring change in preparation for the next commit that
will let -m imply -p.

The old name doesn't match the intention to let not only -c/-cc imply
-p, but also -m, that is not a "combined" format, so we rename the
flag accordingly.

Signed-off-by: Sergey Organov <sorganov@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

revision.h

@@ -195,10 +195,10 @@ struct rev_info {
 			/* Diff-merge flags */
 			explicit_diff_merges: 1,
 			merges_need_diff: 1,
+			merges_imply_patch:1,
 			separate_merges: 1,
 			combine_merges:1,
 			combined_all_paths:1,
-			combined_imply_patch:1,
 			dense_combined_merges:1,
 			first_parent_merges:1;