[PATCH] v9fs: return the correct error when interrupted by signal

If a signal interrupts the user process, v9fs sends a flush request to the
file server and waits for its response.  It error code is incorrectly set
to the error code of the flush message instead of ERESTARTSYS.  The patch
sets the error code to the correct value.

Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@ericvh.myip.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>