Remove compiler warnings and remove not used variables

(Found during build process)

2 files changed, 4 insertions, 3 deletions

diff --git a/extra/comp_err.c b/extra/comp_err.c
index a554fc2437e..85833999d5c 100644
--- a/extra/comp_err.c
+++ b/extra/comp_err.c
@@ -332,13 +332,13 @@ static int create_sys_files(struct languages *lang_head,
     head[30]= csnum;
 
     my_fseek(to, 0l, MY_SEEK_SET, MYF(0));
-    if (my_fwrite(to, head, HEADER_LENGTH, MYF(MY_WME | MY_FNABP)))
+    if (my_fwrite(to, (byte*) head, HEADER_LENGTH, MYF(MY_WME | MY_FNABP)))
       goto err;
 
     for (i= 0; i < row_count; i++)
     {
       int2store(head, file_pos[i]);
-      if (my_fwrite(to, head, 2, MYF(MY_WME | MY_FNABP)))
+      if (my_fwrite(to, (byte*) head, 2, MYF(MY_WME | MY_FNABP)))
 	goto err;
     }
     my_fclose(to, MYF(0));
diff --git a/extra/perror.c b/extra/perror.c
index 6e632b20d96..d68f5230e4a 100644
--- a/extra/perror.c
+++ b/extra/perror.c
@@ -250,7 +250,8 @@ int main(int argc,char *argv[])
         'Unknown Error' (without regard to case).
       */
       if (msg &&
-          my_strnncoll(&my_charset_latin1, msg, 13, "Unknown Error", 13) &&
+          my_strnncoll(&my_charset_latin1, (const uchar*) msg, 13,
+                       (const uchar*) "Unknown Error", 13) &&
           (!unknown_error || strcmp(msg, unknown_error)))
       {
 	found=1;