drivers/pcmcia/m32r_pcc.c: check return from add_pcc_socket

If request_irq() fails it passes the error to the caller.  The caller
now checks it and jumps to the common error path on failure.

Link: http://lkml.kernel.org/r/1474237304-897-3-git-send-email-sudipm.mukherjee@gmail.com
Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>