btrfs-progs: Remove extra 'const' modifiers; they don't do anything.

btrfs-progs: Remove extra 'const' modifiers; they don't do anything.

'const int const *x' means the same thing as 'const int *x' or
'int const *x'; the intent was probably 'const int * const x'.
However, this won't work for the 'suffix' variable, as it has
to be assigned, and making the static tables into const pointers
to const chars leads to a mismatch there.

This was found with clang's duplicate-decl-specifier warning.

Signed-off-by: Adam Buchbinder <abuchbinder@google.com>
Signed-off-by: David Sterba <dsterba@suse.cz>