mac80211: silently accept deletion of non-existant key
mac80211: silently accept deletion of non-existant key

Otherwise, 'iwconfig wlan0 key off' with no key set results in:

	Error for wireless request "Set Encode" (8B2A) :
	    SET failed on device wlan0 ; No such file or directory.

Signed-off-by: John W. Linville <2a53bac7a5d324865ef46ec4c38b2c0fba1456b4@tuxdriver.com>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs