elf: Compile with -Wextra

-Wextra enables a bunch of rather useful checks which this fixes.

This changes the return value for the case when no ELF headers were found
to avoid (ugly-ish) cast of -1 to unsigned.

Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
Changes:
v2:
* cast the return value to (int)
* added missing (long)

1 files changed, 3 insertions, 3 deletions

diff --git a/lib/libelf/elf32.c b/lib/libelf/elf32.c
index 64ea386..45b0015 100644
--- a/lib/libelf/elf32.c
+++ b/lib/libelf/elf32.c
@@ -212,13 +212,13 @@ elf_byteswap_header32(void *file_addr)
  * file.
  * @return Return -1 on error, size of file otherwise.
  */
-long elf_get_file_size32(const void *buffer, const long buffer_size)
+long elf_get_file_size32(const void *buffer, const unsigned long buffer_size)
 {
 	const struct ehdr32 *ehdr = (const struct ehdr32 *) buffer;
 	const uint8_t *buffer_end = buffer + buffer_size;
 	const struct phdr32 *phdr;
 	const struct shdr32 *shdr;
-	long elf_size = -1;
+	unsigned long elf_size = 0;
 	uint16_t entsize;
 	unsigned i;
 
@@ -258,5 +258,5 @@ long elf_get_file_size32(const void *buffer, const long buffer_size)
 	if (elf_size > buffer_size)
 		return -1;
 
-	return elf_size;
+	return (long) elf_size;
 }