memstick: move dev_dbg

id_reg.if_mode might be unitialized when (*mrq)->error is nonzero.  move
dev_dbg() inside the if so that we are sure we can use id_reg values.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>