Fix a typo

Author: eukarpov

winsup/cygwin/scripts/gendef

@@ -426,7 +426,7 @@ stabilize_sig_stack:
 	cbz	w9, 2f				// if no current signal, jump to cleanup
 
 	mov w9, #1				// specify increment
-	staddl w9, [x20]		// attomically increment incyg with a lock
+	staddl w9, [x20]		// atomically increment incyg with a lock
 
 	// prepare arguments and call signal handler
 	mov	x0, #_cygtls.start_offset	// load the _cygtls.start_offset offset
@@ -435,7 +435,7 @@ stabilize_sig_stack:
 
 	// decrement incyg counter
 	mov w9, #-1				// specify decrement
-	staddl w9, [x20]		// attomically decrement incyg with a lock
+	staddl w9, [x20]		// atomically decrement incyg with a lock
 
 	// go to the beginning to handle another signal
 	b	1b