arm64/syscall: Remove duplicate declaration

Commit 6ac19f96 ("arm64: avoid prototype warnings for syscalls")
added missing declarations to various syscall wrapper macros. It
however proved a little too zealous in __SYSCALL_DEFINEx(), as a
declaration for __arm64_sys##name was already present. A declaration
is required before the call to ALLOW_ERROR_INJECTION(), so keep
the original one and remove the new one.

Fixes: 6ac19f96 ("arm64: avoid prototype warnings for syscalls")
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20231109141153.250046-1-kevin.brodsky@arm.com


Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>