umm: remove warnings ISO C forbids an empty translation unit

armsrc/umm_info.c

@@ -1,10 +1,10 @@
-#ifdef UMM_INFO
 
 #include <stdint.h>
 #include <stddef.h>
 #include <stdbool.h>
 
 #include <math.h>
+#ifdef UMM_INFO
 
 /* ----------------------------------------------------------------------------
  * One of the coolest things about this little library is that it's VERY

armsrc/umm_integrity.c

@@ -1,9 +1,9 @@
 /* integrity check (UMM_INTEGRITY_CHECK) {{{ */
-#ifdef UMM_INTEGRITY_CHECK
 
 #include <stdint.h>
 #include <stdbool.h>
 
+#ifdef UMM_INTEGRITY_CHECK
 /*
  * Perform integrity check of the whole heap data. Returns 1 in case of
  * success, 0 otherwise.

armsrc/umm_poison.c

@@ -1,10 +1,10 @@
 /* poisoning (UMM_POISON_CHECK) {{{ */
-#if defined(UMM_POISON_CHECK)
-#define POISON_BYTE (0xa5)
 
 #include <stdint.h>
 #include <stddef.h>
 #include <stdbool.h>
+#if defined(UMM_POISON_CHECK)
+#define POISON_BYTE (0xa5)
 
 /*
  * Yields a size of the poison for the block of size `s`.