libion: clean up whitespace

Convert everything to 4 space indents, no tabs.

Change-Id: I376fad866864f0579b91ffad406e872fcce566ad
diff --git a/libion/include/ion/ion.h b/libion/include/ion/ion.h
index 0451b5a..6ad3ed7 100644
--- a/libion/include/ion/ion.h
+++ b/libion/include/ion/ion.h
@@ -30,9 +30,9 @@
 int ion_open();
 int ion_close(int fd);
 int ion_alloc(int fd, size_t len, size_t align, unsigned int heap_mask,
-	      unsigned int flags, ion_user_handle_t *handle);
+              unsigned int flags, ion_user_handle_t *handle);
 int ion_alloc_fd(int fd, size_t len, size_t align, unsigned int heap_mask,
-		 unsigned int flags, int *handle_fd);
+              unsigned int flags, int *handle_fd);
 int ion_sync_fd(int fd, int handle_fd);
 int ion_free(int fd, ion_user_handle_t handle);
 int ion_map(int fd, ion_user_handle_t handle, size_t length, int prot,