[kernel][mutex] remove the magic test on mutex_init()
[kernel][mutex] remove the magic test on mutex_init()

-This would presumably test for a double init, but really causes more
problems than it's worth.

M1cha/lk,sndnvaps/lk,M1cha/lk,sndnvaps/lk,pablomarx/lk,srodrig1/lk,travisg/lk,sndnvaps/lk,hollanderic/lkstuff,nvll/lk,skabet/lk,M1cha/lk,sndnvaps/lk,minglun-tsai/lk,travisg/lk,pablomarx/lk,nvll/lk,grub4android/lk,ianloic/lk,nvll/lk,pablomarx/lk,ianloic/lk,nvll/lk,GCrean/lk,skabet/lk,minglun-tsai/lk,srodrig1/lk,GCrean/lk,minglun-tsai/lk,littlekernel/lk,skabet/lk,littlekernel/lk,ianloic/lk,GCrean/lk,GCrean/lk,pablomarx/lk,hollanderic/lkstuff,GCrean/lk,littlekernel/lk,grub4android/lk,srodrig1/lk,sndnvaps/lk,travisg/lk,skabet/lk,minglun-tsai/lk,travisg/lk,grub4android/lk,grub4android/lk,M1cha/lk,ErikCorryGoogle/lk,ianloic/lk,srodrig1/lk,hollanderic/lkstuff,hollanderic/lkstuff,M1cha/lk,nvll/lk,grub4android/lk,skabet/lk,littlekernel/lk,srodrig1/lk,ErikCorryGoogle/lk,pablomarx/lk,ErikCorryGoogle/lk,ErikCorryGoogle/lk