UBI: fastmap break out of used PEB search

While searching for PEB matches for each volume in the used PEB list,
the search fails to stop when the PEB is found.  This patch adds
a break in the inner loop to stop the search when it is matched.

Change-Id: I9a717a5a106e2808a594f77abce1c2aa9cd433ff
Signed-off-by: Brian Pomerantz <bapper@gmail.com>
Acked-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Git-commit: 584d4623
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>