x86/syscalls-x86-64.sh: fix bashisms

syscalls-x86-64.sh: 3: syscalls-x86-64.sh: Syntax error: "(" unexpected
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

arch/x86/syscalls-x86-64.sh

 #!/bin/sh
 
-function gen_asm() {
+gen_asm() {
 	in=$1
 	codesout=$2
 	protosout=$3
@@ -33,7 +33,7 @@ function gen_asm() {
 	echo "#endif /* $protosdef */"		>> $protosout
 }
 
-function gen_exec() {
+gen_exec() {
 	in=$1
 	codecout=$2