sound/oss/dmasound: Remove superfluous "break"

Remove superfluous "break", as there is a "return" before them.
Signed-off-by: zuoqilin <zuoqilin@yulong.com>
Link: https://lore.kernel.org/r/20210527030445.1201-1-zuoqilin1@163.comSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/oss/dmasound/dmasound_core.c

@@ -1229,31 +1229,22 @@ static char *get_afmt_string(int afmt)
         switch(afmt) {
             case AFMT_MU_LAW:
                 return "mu-law";
-                break;
             case AFMT_A_LAW:
                 return "A-law";
-                break;
             case AFMT_U8:
                 return "unsigned 8 bit";
-                break;
             case AFMT_S8:
                 return "signed 8 bit";
-                break;
             case AFMT_S16_BE:
                 return "signed 16 bit BE";
-                break;
             case AFMT_U16_BE:
                 return "unsigned 16 bit BE";
-                break;
             case AFMT_S16_LE:
                 return "signed 16 bit LE";
-                break;
             case AFMT_U16_LE:
                 return "unsigned 16 bit LE";
-                break;
 	    case 0:
 		return "format not set" ;
-		break ;
             default:
                 break ;
         }