Fix some of the things clang --analyze flagged

code/renderergl1/tr_image.c

@@ -326,7 +326,6 @@ static void ResampleTexture( unsigned *in, int inwidth, int inheight, unsigned *
 	for (i=0 ; i<outheight ; i++, out += outwidth) {
 		inrow = in + inwidth*(int)((i+0.25)*inheight/outheight);
 		inrow2 = in + inwidth*(int)((i+0.75)*inheight/outheight);
-		frac = fracstep >> 1;
 		for (j=0 ; j<outwidth ; j++) {
 			pix1 = (byte *)inrow + p1[j];
 			pix2 = (byte *)inrow + p2[j];