patch 9.0.0828: various typos

Problem:    Various typos.
Solution:   Correct typos. (closes #11432)
diff --git a/src/charset.c b/src/charset.c
index 0e93077..fe1569c 100644
--- a/src/charset.c
+++ b/src/charset.c
@@ -2291,7 +2291,7 @@
 	}
 	else
 	{
-	    // prevent a larg unsigned number to become negative
+	    // prevent a large unsigned number to become negative
 	    if (un > VARNUM_MAX)
 		un = VARNUM_MAX;
 	    *nptr = (varnumber_T)un;