Fix GetRandom in sanitizer_fuchsia.cpp (llvm#110155)

The `zx_cprng_draw` system call has no limit on how much you can draw.

Co-authored-by: Marco Vanotti <[email protected]>

Author: mvanotti

compiler-rt/lib/sanitizer_common/sanitizer_fuchsia.cpp

@@ -523,7 +523,6 @@ uptr ReadLongProcessName(/*out*/ char *buf, uptr buf_len) {
 uptr MainThreadStackBase, MainThreadStackSize;
 
 bool GetRandom(void *buffer, uptr length, bool blocking) {
-  CHECK_LE(length, ZX_CPRNG_DRAW_MAX_LEN);
   _zx_cprng_draw(buffer, length);
   return true;
 }