[PATCH] modules: prevent overriding of symbols

Ensure that an exported symbol does not already exist in the kernel or in
some other module's exported symbol table.  This is done by checking the
symbol tables for the exported symbol at the time of loading the module.
Currently this is done after the relocation of the symbol.

Signed-off-by: Ashutosh Naik <ashutosh.naik@gmail.com>
Signed-off-by: Anand Krishnan <anandhkrishnan@yahoo.co.in>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>