Rename syscall_fixup to syscall_fixup_on_sysenter

* defs.h: Tweak comment.
* syscall.c: Rename syscall_fixup to syscall_fixup_on_sysenter.
(trace_syscall_entering): Use new finction name.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
diff --git a/syscall.c b/syscall.c
index f4ae508..db53809 100644
--- a/syscall.c
+++ b/syscall.c
@@ -1245,7 +1245,7 @@
  *    ("????" etc) and bail out.
  */
 static int
-syscall_fixup(struct tcb *tcp)
+syscall_fixup_on_sysenter(struct tcb *tcp)
 {
 #ifdef USE_PROCFS
 	int scno = known_scno(tcp);
@@ -1697,7 +1697,7 @@
 	if (res == 0)
 		return res;
 	if (res == 1)
-		res = syscall_fixup(tcp);
+		res = syscall_fixup_on_sysenter(tcp);
 	if (res == 0)
 		return res;
 	if (res == 1)