Fix various warnings

code/renderercommon/tr_image_tga.c

@@ -42,7 +42,7 @@ void R_LoadTGA ( const char *name, byte **pic, int *width, int *height)
 {
 	unsigned	columns, rows, numPixels;
 	byte	*pixbuf;
-	int		row, column;
+	unsigned	row, column;
 	byte	*buf_p;
 	byte	*end;
 	union {
@@ -190,7 +190,8 @@ void R_LoadTGA ( const char *name, byte **pic, int *width, int *height)
 		}
 	}
 	else if (targa_header.image_type==10) {   // Runlength encoded RGB images
-		unsigned char red,green,blue,alphabyte,packetHeader,packetSize,j;
+		unsigned char red = 0, green = 0, blue = 0, alphabyte = 0;
+		unsigned char packetHeader, packetSize, j;
 
 		for(row=rows-1; row>=0; row--) {
 			pixbuf = targa_rgba + row*columns*4;