[Piglit] Maybe some mistake in cl builtin-char-abs-1.0.generated

[He Junyan]

about test case "builtin-char-abs-1.0.generated"

The kernel will generate as:

kernel void test_2_abs_char(global uchar* out, global char* in0){
    vstore2(abs(vload2(0, in0)), 0, out);
}

Which will cause the vstore function fail.

here, I think the vstore2 will have the prototype:
vstore2(char2 vect,  int offset,  uchar* out);

but the spec says:
void vstoren (gentypen data, size_t offset, __local gentype *p)

So the gentype must be same, and there is no builtin conversion rule 
between uchar2 to char2 or uchar * to char *,
this case will always fail.

Please uniform the in and out type