powerpc/e500: Simplify pte_mkexec()

Commit b6cb20fd ("powerpc/book3e: Fix set_memory_x() and
set_memory_nx()") implemented a more elaborated version of
pte_mkwrite() suitable for both kernel and user pages. That was
needed because set_memory_x() was using pte_mkwrite(). But since
commit a4c182ec ("powerpc/set_memory: Avoid spinlock recursion
in change_page_attr()") pte_mkwrite() is not used anymore by
set_memory_x() so pte_mkwrite() can be simplified as it is only
used for user pages.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/cdc822322fe2ff4b0f5ecfde71d09d950b1c7557.1695659959.git.christophe.leroy@csgroup.eu

arch/powerpc/include/asm/nohash/pte-e500.h

@@ -115,10 +115,7 @@ static inline pte_t pte_mkuser(pte_t pte)
 
 static inline pte_t pte_mkexec(pte_t pte)
 {
-	if (pte_val(pte) & _PAGE_BAP_UR)
 	return __pte((pte_val(pte) & ~_PAGE_BAP_SX) | _PAGE_BAP_UX);
-	else
-		return __pte((pte_val(pte) & ~_PAGE_BAP_UX) | _PAGE_BAP_SX);
 }
 #define pte_mkexec pte_mkexec