doc: SubmittingPatches: remove dead link, kerneltrap.org no longer works

kerneltrap.org no longer works, remove the dead reference

Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Documentation/SubmittingDrivers

@@ -146,10 +146,6 @@ LWN.net:
 	Porting drivers from prior kernels to 2.6:
 		http://lwn.net/Articles/driver-porting/
 
-KernelTrap:
-	Occasional Linux kernel articles and developer interviews
-	http://kerneltrap.org/
-
 KernelNewbies:
 	Documentation and assistance for new kernel programmers
 	http://kernelnewbies.org/