umpf: call rev-parse on manually selected local branches as well

When umpf compares branches between all of the known remotes, it will now
prompt the user when it discovers a branch that includes additional commits
compared to the one on the selected remote.

If the user confirms, the branch name is taken as is, which would result in
an umpf-hashinfo of e.g. heads/v6.4/topic/something, which breaks the
ability of doing identical umpfs.

To restore that ability, we use the result of calling rev-parse on the
${branch}, which is conveniently available already in ${b}.

Fixes: 000e642 ("umpf: add branch choice in case of additional commits")
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>

umpf

@@ -394,7 +394,7 @@ find_branch_rev() {
 				local choice=""
 				read -e -i n -p "Use ${branch} instead? [y/n]: " choice
 				if [ "${choice}" == "y" ]; then
-					reply="${branch}"
+					reply="${b}"
 				fi
 			fi
 		fi