migration/ram.c: fix typos in comments

Signed-off-by: NWei Yang <richardw.yang@linux.intel.com>
Message-Id: <20190510233729.15554-1-richardw.yang@linux.intel.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

migration/ram.c

@@ -917,7 +917,7 @@ struct {
  *    - to make easier to know what to free at the end of migration
  *
  * This way we always know who is the owner of each "pages" struct,
- * and we don't need any loocking.  It belongs to the migration thread
+ * and we don't need any locking.  It belongs to the migration thread
  * or to the channel thread.  Switching is safe because the migration
  * thread is using the channel mutex when changing it, and the channel
  * have to had finish with its own, otherwise pending_job can't be
@@ -1630,7 +1630,7 @@ static int save_xbzrle_page(RAMState *rs, uint8_t **current_data,
 /**
  * migration_bitmap_find_dirty: find the next dirty page from start
  *
- * Returns the byte offset within memory region of the start of a dirty page
+ * Returns the page offset within memory region of the start of a dirty page
  *
  * @rs: current RAM state
  * @rb: RAMBlock where to search for dirty pages
@@ -2144,7 +2144,7 @@ retry:
  * find_dirty_block: find the next dirty page and update any state
  * associated with the search process.
  *
- * Returns if a page is found
+ * Returns true if a page is found
  *
  * @rs: current RAM state
  * @pss: data about the state of the current dirty page scan
@@ -2240,7 +2240,7 @@ static RAMBlock *unqueue_page(RAMState *rs, ram_addr_t *offset)
  *
  * Skips pages that are already sent (!dirty)
  *
- * Returns if a queued page is found
+ * Returns true if a queued page is found
  *
  * @rs: current RAM state
  * @pss: data about the state of the current dirty page scan
@@ -3447,7 +3447,7 @@ static int ram_save_iterate(QEMUFile *f, void *opaque)
 
         /* we want to check in the 1st loop, just in case it was the 1st time
            and we had to sync the dirty bitmap.
-           qemu_get_clock_ns() is a bit expensive, so we only check each some
+           qemu_clock_get_ns() is a bit expensive, so we only check each some
            iterations
         */
         if ((i & 63) == 0) {