mariadb: disable valgrind
mariadb: disable valgrind

Issue: LIN7-632

Fixed undetermined build when there is valgrind:
my_context.c:28:31: fatal error: valgrind/valgrind.h: No such file or directory

(LOCAL REV: NOT UPSTREAM) -- Sent to meta-oe on 20140829

Signed-off-by: Robert Yang <58c339bb2d6e36747c1485f8911298e2be82d9f6@windriver.com>

WindRiver-OpenSourceLabs/meta-oe-subset,WindRiver-OpenSourceLabs/meta-oe-subset