Fix format warn (#96)

* fix warning: format '%x' expects argument of type 'unsigned int', but argument 4 has type 'long unsigned int'
* fix warning: implicit declaration of function 'up_init_exidx'

binfmt/libelf/libelf_load.c

@@ -51,6 +51,7 @@
 
 #include <nuttx/arch.h>
 #include <nuttx/addrenv.h>
+#include <nuttx/elf.h>
 #include <nuttx/mm/mm.h>
 #include <nuttx/binfmt/elf.h>
 

net/procfs/netdev_statistics.c

@@ -538,7 +538,7 @@ static int netprocfs_errors(FAR struct netprocfs_file_s *netfile)
   stats = &dev->d_statistics;
 
   return snprintf(netfile->line, NET_LINELEN , "\tTotal Errors: %08x\n\n",
-                  (unsigned long)stats->errors);
+                  stats->errors);
 }
 #endif /* CONFIG_NETDEV_STATISTICS */