.gitignore: prefix local generated files with a slash

The pattern prefixed with '/' matches files in the same directory,
but not ones in sub-directories.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Andra Paraschiv <andraprs@amazon.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Gabriel Krisman Bertazi <krisman@collabora.com>

scripts/.gitignore

@@ -1,11 +1,11 @@
 # SPDX-License-Identifier: GPL-2.0-only
-bin2c
-kallsyms
-unifdef
-recordmcount
-sorttable
-asn1_compiler
-extract-cert
-sign-file
-insert-sys-cert
+/asn1_compiler
+/bin2c
+/extract-cert
+/insert-sys-cert
+/kallsyms
 /module.lds
+/recordmcount
+/sign-file
+/sorttable
+/unifdef