drm/amdgpu: signedness bug in amdgpu_cs_parser_init()

The "i" variable should be signed or it leads to a crash in the error
handling code.

Fixes: 1d263474c441 ('drm/amdgpu: unwind properly in amdgpu_cs_parser_init()')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c

@@ -156,7 +156,8 @@ int amdgpu_cs_parser_init(struct amdgpu_cs_parser *p, void *data)
 	uint64_t *chunk_array_user;
 	uint64_t *chunk_array;
 	struct amdgpu_fpriv *fpriv = p->filp->driver_priv;
-	unsigned size, i;
+	unsigned size;
+	int i;
 	int ret;
 
 	if (cs->in.num_chunks == 0)