Fix printf format to use %zd when printing sizes

Using %ld as we were doing raises compiler warnings on 32 bit platforms.

Reported by Andres Freund.
Discussion: https://postgr.es/m/20170407214022.fidezl2e6rk3tuiz@alap3.anarazel.de

src/backend/statistics/dependencies.c

@@ -511,7 +511,7 @@ statext_dependencies_deserialize(bytea *data)
 		return NULL;
 
 	if (VARSIZE_ANY_EXHDR(data) < SizeOfDependencies)
-		elog(ERROR, "invalid MVDependencies size %ld (expected at least %ld)",
+		elog(ERROR, "invalid MVDependencies size %zd (expected at least %zd)",
 			 VARSIZE_ANY_EXHDR(data), SizeOfDependencies);
 
 	/* read the MVDependencies header */
@@ -547,7 +547,7 @@ statext_dependencies_deserialize(bytea *data)
 							   sizeof(AttrNumber) * 2);
 
 	if (VARSIZE_ANY_EXHDR(data) < min_expected_size)
-		elog(ERROR, "invalid dependencies size %ld (expected at least %ld)",
+		elog(ERROR, "invalid dependencies size %zd (expected at least %zd)",
 			 VARSIZE_ANY_EXHDR(data), min_expected_size);
 
 	/* allocate space for the MCV items */

src/backend/statistics/mvdistinct.c

@@ -238,7 +238,7 @@ statext_ndistinct_deserialize(bytea *data)
 
 	/* we expect at least the basic fields of MVNDistinct struct */
 	if (VARSIZE_ANY_EXHDR(data) < SizeOfMVNDistinct)
-		elog(ERROR, "invalid MVNDistinct size %ld (expected at least %ld)",
+		elog(ERROR, "invalid MVNDistinct size %zd (expected at least %zd)",
 			 VARSIZE_ANY_EXHDR(data), SizeOfMVNDistinct);
 
 	/* initialize pointer to the data part (skip the varlena header) */
@@ -274,7 +274,7 @@ statext_ndistinct_deserialize(bytea *data)
 	if (VARSIZE_ANY_EXHDR(data) < minimum_size)
 		ereport(ERROR,
 				(errcode(ERRCODE_DATA_CORRUPTED),
-				 errmsg("invalid MVNDistinct size %ld (expected at least %ld)",
+				 errmsg("invalid MVNDistinct size %zd (expected at least %zd)",
 						VARSIZE_ANY_EXHDR(data), minimum_size)));
 
 	/*