doio, growfiles: Use standard signal name SIGCHLD instead of SIGCLD

SIGCLD is synonymous with SIGCHLD, but the former is non-standard
and not supported by some C libraries such as musl.

Signed-off-by: Rostislav Skudnov <rostislav@tuxera.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Eryu Guan <eguan@redhat.com>

ltp/doio.c

@@ -362,7 +362,7 @@ char	**argv;
 		case SIGTSTP:
 		case SIGSTOP:
 		case SIGCONT:
-		case SIGCLD:
+		case SIGCHLD:
 		case SIGBUS:
 		case SIGSEGV:
 		case SIGQUIT:

ltp/growfiles.c

@@ -1389,7 +1389,7 @@ set_sig()
 #ifdef SIGRESTART
 	        case SIGRESTART:
 #endif /* SIGRESTART */
-                case SIGCLD:
+                case SIGCHLD:
                     break;
 
                 default: