[PATCH] isdn/gigaset/common.c: fix a memory leak

Fix a memory leak spotted by the Coverity checker if
(!try_module_get(owner)).

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>