patch 8.2.4928: various white space and cosmetic mistakes

Problem:    Various white space and cosmetic mistakes.
Solution:   Change spaces to tabs, improve comments.
diff --git a/src/typval.c b/src/typval.c
index afe4e62..ba98f1e 100644
--- a/src/typval.c
+++ b/src/typval.c
@@ -971,7 +971,7 @@
 	case VAR_SPECIAL:
 	    STRCPY(buf, get_var_special_name(varp->vval.v_number));
 	    return buf;
-        case VAR_BLOB:
+	case VAR_BLOB:
 	    emsg(_(e_using_blob_as_string));
 	    break;
 	case VAR_JOB: