Currently, modprobe fails with no output by default if the
search paths it tries are missing:

$ modprobe -S notakernel dm-crypt
$
$ modprobe -S notakernel lkjjweiojo
$

This is fairly cryptic and not at all obvious there is a problem
unless the error code is checked or verbose flags are used.
Update the error message to indicate a problem and print out the
directory that failed.
---
 libkmod/libkmod-internal.h | 2 --
 libkmod/libkmod.h          | 1 +
 tools/modprobe.c           | 7 +++----
 3 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/libkmod/libkmod-internal.h b/libkmod/libkmod-internal.h
index 3e9839d..4d9db6b 100644
--- a/libkmod/libkmod-internal.h
+++ b/libkmod/libkmod-internal.h

@@ -85,8 +85,6 @@ struct kmod_list *kmod_list_append_list(struct kmod_list *list1, struct kmod_lis
                container_of(list_entry->node.prev, struct kmod_list, node)))

 /* libkmod.c */
-const char *kmod_get_dirname(const struct kmod_ctx *ctx) __attribute__((nonnull(1)));
-
 int kmod_lookup_alias_from_config(struct kmod_ctx *ctx, const char *name, struct kmod_list **list) __attribute__((nonnull(1, 2, 3)));
 int kmod_lookup_alias_from_symbols_file(struct kmod_ctx *ctx, const char *name, struct kmod_list **list) __attribute__((nonnull(1, 2, 3)));
 int kmod_lookup_alias_from_aliases_file(struct kmod_ctx *ctx, const char *name, struct kmod_list **list) __attribute__((nonnull(1, 2, 3)));

diff --git a/libkmod/libkmod.h b/libkmod/libkmod.h
index fe53a59..f9e33c6 100644
--- a/libkmod/libkmod.h
+++ b/libkmod/libkmod.h

@@ -51,6 +51,7 @@ void kmod_set_log_priority(struct kmod_ctx *ctx, int priority);
 void *kmod_get_userdata(const struct kmod_ctx *ctx);
 void kmod_set_userdata(struct kmod_ctx *ctx, const void *userdata);

+const char *kmod_get_dirname(const struct kmod_ctx *ctx);