patch 8.2.2160: various typos

Problem:    Various typos.
Solution:   Fix spelling mistakes. (closes #7494)
diff --git a/src/cmdexpand.c b/src/cmdexpand.c
index f3e19bc..11cb0e3 100644
--- a/src/cmdexpand.c
+++ b/src/cmdexpand.c
@@ -1049,7 +1049,7 @@
 		++p;
     }
 
-    // If the cursor is touching the command, and it ends in an alpha-numeric
+    // If the cursor is touching the command, and it ends in an alphanumeric
     // character, complete the command name.
     if (*p == NUL && ASCII_ISALNUM(p[-1]))
 	return NULL;