memblock tests: update zeroed memory check for memblock_alloc_* tests

Update the assert in memblock_alloc_try_nid() and memblock_alloc_from()
tests that checks whether the memory is cleared so that it checks the
entire chunk of allocated memory instead of just the first byte.
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Shaoqin Huang <shaoqin.huang@intel.com>
Signed-off-by: Rebecca Mckeever <remckee0@gmail.com>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Link: https://lore.kernel.org/r/24b3271751756100142e65b75284d43b4d30c9b7.1661578349.git.remckee0@gmail.com

tools/testing/memblock/tests/alloc_helpers_api.c

@@ -19,7 +19,6 @@ static int alloc_from_simple_generic_check(void)
 {
 	struct memblock_region *rgn = &memblock.reserved.regions[0];
 	void *allocated_ptr = NULL;
-	char *b;
 
 	PREFIX_PUSH();
 
@@ -31,10 +30,9 @@ static int alloc_from_simple_generic_check(void)
 	min_addr = memblock_end_of_DRAM() - SMP_CACHE_BYTES;
 
 	allocated_ptr = memblock_alloc_from(size, SMP_CACHE_BYTES, min_addr);
-	b = (char *)allocated_ptr;
 
 	ASSERT_NE(allocated_ptr, NULL);
-	ASSERT_EQ(*b, 0);
+	ASSERT_MEM_EQ(allocated_ptr, 0, size);
 
 	ASSERT_EQ(rgn->size, size);
 	ASSERT_EQ(rgn->base, min_addr);
@@ -66,7 +64,6 @@ static int alloc_from_misaligned_generic_check(void)
 {
 	struct memblock_region *rgn = &memblock.reserved.regions[0];
 	void *allocated_ptr = NULL;
-	char *b;
 
 	PREFIX_PUSH();
 
@@ -79,10 +76,9 @@ static int alloc_from_misaligned_generic_check(void)
 	min_addr = memblock_end_of_DRAM() - (SMP_CACHE_BYTES * 2 - 1);
 
 	allocated_ptr = memblock_alloc_from(size, SMP_CACHE_BYTES, min_addr);
-	b = (char *)allocated_ptr;
 
 	ASSERT_NE(allocated_ptr, NULL);
-	ASSERT_EQ(*b, 0);
+	ASSERT_MEM_EQ(allocated_ptr, 0, size);
 
 	ASSERT_EQ(rgn->size, size);
 	ASSERT_EQ(rgn->base, memblock_end_of_DRAM() - SMP_CACHE_BYTES);