alpha: fix typos in a comment

"kerne" -> "kernel"

Signed-off-by: tangchunyou <[e-mail]>
Signed-off-by: Matt Turner <[e-mail]>

arch/alpha/boot/bootpz.c

···
 	START_ADDR	KSEG address of the entry point of kernel code.
 
 	ZERO_PGE	KSEG address of page full of zeroes, but 
-			upon entry to kerne cvan be expected
+			upon entry to kernel, it can be expected
 			to hold the parameter list and possible
 			INTRD information.