malloc: set errno to ENOMEM when malloc fail

fix LTP case ltp_threads_pthread_cond_init_s_c error:
"Test ltp_threads_pthread_cond_init_s_c unresolved: got 38
(Invalid system call number) on line 236 (Memory not full)"

Signed-off-by: yangyalei <yangyalei@xiaomi.com>

ltp: fix review questions

Signed-off-by: yangyalei <yangyalei@xiaomi.com>

mm/umm_heap/umm_malloc.c

@@ -26,7 +26,7 @@
 
 #include <stdlib.h>
 #include <unistd.h>
-
+#include <errno.h>
 #include <nuttx/mm/mm.h>
 
 #include "umm_heap/umm_heap.h"
@@ -57,8 +57,16 @@ FAR void *malloc(size_t size)
 
   return memalign(sizeof(FAR void *), size);
 #else
+  FAR void *ret;
+
   /* Use mm_malloc() because it implements the clear */
 
-  return mm_malloc(USR_HEAP, size);
+  ret = mm_malloc(USR_HEAP, size);
+  if (!ret)
+    {
+      set_errno(ENOMEM);
+    }
+
+  return ret;
 #endif
 }

mm/umm_heap/umm_memalign.c

@@ -26,7 +26,7 @@
 
 #include <stdlib.h>
 #include <unistd.h>
-
+#include <errno.h>
 #include <nuttx/mm/mm.h>
 
 #include "umm_heap/umm_heap.h"
@@ -86,6 +86,14 @@ FAR void *memalign(size_t alignment, size_t size)
 
   return mem;
 #else
-  return mm_memalign(USR_HEAP, alignment, size);
+  FAR void *ret;
+
+  ret = mm_memalign(USR_HEAP, alignment, size);
+  if (!ret)
+    {
+      set_errno(ENOMEM);
+    }
+
+  return ret;
 #endif
 }

mm/umm_heap/umm_realloc.c

@@ -26,7 +26,7 @@
 
 #include <stdlib.h>
 #include <unistd.h>
-
+#include <errno.h>
 #include <nuttx/mm/mm.h>
 
 #include "umm_heap/umm_heap.h"
@@ -88,6 +88,14 @@ FAR void *realloc(FAR void *oldmem, size_t size)
 
   return mem;
 #else
-  return mm_realloc(USR_HEAP, oldmem, size);
+  FAR void *ret;
+
+  ret = mm_realloc(USR_HEAP, oldmem, size);
+  if (!ret)
+    {
+      set_errno(ENOMEM);
+    }
+
+  return ret;
 #endif
 }

mm/umm_heap/umm_zalloc.c

@@ -26,7 +26,7 @@
 
 #include <stdlib.h>
 #include <string.h>
-
+#include <errno.h>
 #include <nuttx/mm/mm.h>
 
 #include "umm_heap/umm_heap.h"
@@ -63,8 +63,16 @@ FAR void *zalloc(size_t size)
 
   return mem;
 #else
+  FAR void *ret;
+
   /* Use mm_zalloc() because it implements the clear */
 
-  return mm_zalloc(USR_HEAP, size);
+  ret = mm_zalloc(USR_HEAP, size);
+  if (!ret)
+    {
+      set_errno(ENOMEM);
+    }
+
+  return ret;
 #endif
 }