l10n: fr: fix transcation of "dir"

"dir" was translated to the same string at builtin/log.c:1236,
but, also at that code line, "<dir>" was translate to "<répertoire>".

Before this commit, git format-patch -h would output "-o,
--output-directory <dir>" and <répertoire> in its description.

Use <répertoire> in both the parameter and description.

Signed-off-by: Vasco Almeida <vascomalmeida@sapo.pt>

Author: vascool

po/fr.po

@@ -6197,7 +6197,7 @@ msgstr "convertir en un dépôt complet"
 
 #: builtin/fetch.c:122 builtin/log.c:1236
 msgid "dir"
-msgstr "dir"
+msgstr "répertoire"
 
 #: builtin/fetch.c:123
 msgid "prepend this to submodule path output"