[PATCH] Char: mxser_new, fix twice resource releasing

Because brd->info is not NULLed, resources are released twice.  NULL it in
pci_remove function.  Also take care of retval and releasing in pci_probe --
mxser_initbrd alreasy releases resource, do not do it again in fail path in
probe function.

Cc: Sergei Organov <osv@javad.com>
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>