patch 8.2.3914: various spelling mistakes in comments

Problem:    Various spelling mistakes in comments.
Solution:   Fix the mistakes. (Dominique Pellé, closes #9416)
diff --git a/src/gui_photon.c b/src/gui_photon.c
index c89d781..ea8e5e4 100644
--- a/src/gui_photon.c
+++ b/src/gui_photon.c
@@ -487,7 +487,7 @@
 		    if (key->key_cap >= Pk_KP_Enter && key->key_cap <= Pk_KP_9
 			    && (key->key_mods & Pk_KM_Num_Lock))
 		    {
-			// FIXME: For now, just map the key to a ascii value
+			// FIXME: For now, just map the key to an ascii value
 			// (see <photon/PkKeyDef.h>)
 			ch = key->key_cap - 0xf080;
 		    }