kernel: syscalls: Change handlers namespace

According C99 the first 31 characters of an identifier must be unique.
Shortening the namespace of the generated objects to achieve it.

C99 - 5.2.4.1
MISRA-C rule 5.1

Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
diff --git a/scripts/gen_syscall_header.py b/scripts/gen_syscall_header.py
index 1305096..cab36cd 100755
--- a/scripts/gen_syscall_header.py
+++ b/scripts/gen_syscall_header.py
@@ -70,7 +70,7 @@
     # from gc-sections; these references will not consume space.
 
     sys.stdout.write(
-        "static _GENERIC_SECTION(hndlr_ref) __used void *href = (void *)&_handler_##name; \\\n")
+        "static _GENERIC_SECTION(hndlr_ref) __used void *href = (void *)&hdlr_##name; \\\n")
     tabs(tabcount)
     if (ret != Retval.VOID):
         sys.stdout.write("return (ret)")