cocci: avoid self-references in object_id transformations

The object_id functions oid_to_hex, oid_to_hex_r, oidclr, oidcmp, and
oidcpy are defined as wrappers of their legacy counterparts sha1_to_hex,
sha1_to_hex_r, hashclr, hashcmp, and hashcpy, respectively.  Make sure
that the Coccinelle transformations for converting legacy function calls
are not applied to these wrappers themselves, which would result in
tautological declarations.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/coccinelle/object_id.cocci

@@ -17,10 +17,13 @@ expression E1;
 + oid_to_hex(&E1)
 
 @@
+identifier f != oid_to_hex;
 expression E1;
 @@
+  f(...) {...
 - sha1_to_hex(E1->hash)
 + oid_to_hex(E1)
+  ...}
 
 @@
 expression E1, E2;
@@ -29,10 +32,13 @@ expression E1, E2;
 + oid_to_hex_r(E1, &E2)
 
 @@
+identifier f != oid_to_hex_r;
 expression E1, E2;
 @@
+   f(...) {...
 - sha1_to_hex_r(E1, E2->hash)
 + oid_to_hex_r(E1, E2)
+  ...}
 
 @@
 expression E1;
@@ -41,10 +47,13 @@ expression E1;
 + oidclr(&E1)
 
 @@
+identifier f != oidclr;
 expression E1;
 @@
+  f(...) {...
 - hashclr(E1->hash)
 + oidclr(E1)
+  ...}
 
 @@
 expression E1, E2;
@@ -53,10 +62,13 @@ expression E1, E2;
 + oidcmp(&E1, &E2)
 
 @@
+identifier f != oidcmp;
 expression E1, E2;
 @@
+  f(...) {...
 - hashcmp(E1->hash, E2->hash)
 + oidcmp(E1, E2)
+  ...}
 
 @@
 expression E1, E2;
@@ -77,10 +89,13 @@ expression E1, E2;
 + oidcpy(&E1, &E2)
 
 @@
+identifier f != oidcpy;
 expression E1, E2;
 @@
+  f(...) {...
 - hashcpy(E1->hash, E2->hash)
 + oidcpy(E1, E2)
+  ...}
 
 @@
 expression E1, E2;