kallsyms: store type information in its own array

When a module is loaded, its symbols' Elf_Sym information is stored
in a symtab.  Further, type information is also captured.  Since
Elf_Sym has no type field, historically the st_info field has been
hijacked for storing type:  st_info was overwritten.

commit 5439c985 ("module: Overwrite
st_size instead of st_info") changes that practice, as its one-liner
indicates.  Unfortunately, this change overwrites symbol size,
information that a tool like DTrace expects to find.

Allocate a typetab array to store type information so that no Elf_Sym
field needs to be overwritten.

Fixes: 5439c985 ("module: Overwrite st_size instead of st_info")
Signed-off-by: Eugene Loh <eugene.loh@oracle.com>
Reviewed-by: Nick Alcock <nick.alcock@oracle.com>
[jeyu: renamed typeoff -> typeoffs ]
Signed-off-by: Jessica Yu <jeyu@kernel.org>