Spelling fixes.

lisp/org/org.el

@@ -7571,7 +7571,7 @@ headline or the item and create a new headline/item with the text
 in the current line after point \(see `org-M-RET-may-split-line'
 on how to modify this behavior).
-With one universal prefirx argument, set the user option
+With one universal prefix argument, set the user option
 `org-insert-heading-respect-content' to t for the duration of
 the command.  This modifies the behavior described above in this
 ways: on list items and at the beginning of normal lines, force

src/xfaces.c

@@ -3122,7 +3122,7 @@ FRAME 0 means change the face on all frames, and change the default
 
               /* FIXME:
                  If frame is t, and selected frame is a tty frame, the font
-                 can't be realized.  An improvement wuld be to loop over frames
+                 can't be realized.  An improvement would be to loop over frames
                  for a non-tty frame and use that.  See discussion in
                  bug#18573.
               */