unreachable code warning fixes for tools (nw)

src/mess/tools/imgtool/modules/hp48.c

@@ -297,7 +297,8 @@ static int find_file(hp48_partition* p, const char* filename, int *ptotalsize, i
 
 		}
 
-		return -1;
+		// never executed
+		//return -1;
 }
 
 

src/mess/tools/imgtool/modules/psion.c

@@ -242,7 +242,6 @@ char *stream_getline(imgtool_stream *source, UINT16 max_len)
 					stream_seek(source, -1, SEEK_CUR);
 			case '\n':
 				return line;
-				break;
 			default:
 				line[pos++] = data;
 				break;

src/tools/nltool.c

@@ -182,7 +182,6 @@ protected:
 				vprintf(format, ap);
 				printf("\n");
 				throw;
-				break;
 		}
 	}