Fix some leftovers after mynewt move (PR #52)

- caps.c was now updated (missed this one!).
- *_OVERWRITE_ONLY flag was now also updated.
diff --git a/boot/bootutil/src/loader.c b/boot/bootutil/src/loader.c
index a328172..d42c40e 100644
--- a/boot/bootutil/src/loader.c
+++ b/boot/bootutil/src/loader.c
@@ -645,7 +645,7 @@
  * @return                      The number of bytes comprised by the
  *                                  [first-sector, last-sector] range.
  */
-#ifndef BOOTUTIL_OVERWRITE_ONLY
+#ifndef MCUBOOT_OVERWRITE_ONLY
 static uint32_t
 boot_copy_sz(int last_sector_idx, int *out_first_sector_idx)
 {
@@ -669,7 +669,7 @@
     *out_first_sector_idx = i + 1;
     return sz;
 }
-#endif /* not BOOTUTIL_OVERWRITE_ONLY */
+#endif /* !MCUBOOT_OVERWRITE_ONLY */
 
 /**
  * Erases a region of flash.
@@ -845,7 +845,7 @@
  *
  * @return                      0 on success; nonzero on failure.
  */
-#ifndef BOOTUTIL_OVERWRITE_ONLY
+#ifndef MCUBOOT_OVERWRITE_ONLY
 static void
 boot_swap_sectors(int idx, uint32_t sz, struct boot_status *bs)
 {
@@ -978,7 +978,7 @@
         assert(rc == 0);
     }
 }
-#endif /* not BOOTUTIL_OVERWRITE_ONLY */
+#endif /* !MCUBOOT_OVERWRITE_ONLY */
 
 /**
  * Swaps the two images in flash.  If a prior copy operation was interrupted
@@ -992,7 +992,7 @@
  *
  * @return                      0 on success; nonzero on failure.
  */
-#ifdef BOOTUTIL_OVERWRITE_ONLY
+#ifdef MCUBOOT_OVERWRITE_ONLY
 static int
 boot_copy_image(struct boot_status *bs)
 {