Fix some compiler warnings

Some of the buildfarm members with some old gcc versions have been
complaining about an always-true test for a NULL pointer caused by a
combination of SOFT_ERROR_OCCURRED() and a local ErrorSaveContext
variable.

These warnings are taken care of by removing SOFT_ERROR_OCCURRED(),
switching to a direct variable check, like 56b1e88c80.

Oversights in e1405aa5e3 and 44eba8f06e.

Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/1341064.1764895052@sss.pgh.pa.us

src/backend/utils/adt/pg_dependencies.c

@@ -494,7 +494,7 @@ dependencies_scalar(void *state, char *token, JsonTokenType tokentype)
 		case DEPS_EXPECT_ATTNUM:
 			attnum = pg_strtoint16_safe(token, (Node *) &escontext);
 
-			if (SOFT_ERROR_OCCURRED(&escontext))
+			if (escontext.error_occurred)
 			{
 				errsave(parse->escontext,
 						errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
@@ -539,7 +539,7 @@ dependencies_scalar(void *state, char *token, JsonTokenType tokentype)
 			parse->dependency = (AttrNumber)
 				pg_strtoint16_safe(token, (Node *) &escontext);
 
-			if (SOFT_ERROR_OCCURRED(&escontext))
+			if (escontext.error_occurred)
 			{
 				errsave(parse->escontext,
 						errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
@@ -569,7 +569,7 @@ dependencies_scalar(void *state, char *token, JsonTokenType tokentype)
 			parse->degree = float8in_internal(token, NULL, "double",
 											  token, (Node *) &escontext);
 
-			if (SOFT_ERROR_OCCURRED(&escontext))
+			if (escontext.error_occurred)
 			{
 				errsave(parse->escontext,
 						errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),

src/backend/utils/adt/pg_ndistinct.c

@@ -435,7 +435,7 @@ ndistinct_scalar(void *state, char *token, JsonTokenType tokentype)
 		case NDIST_EXPECT_ATTNUM:
 			attnum = pg_strtoint16_safe(token, (Node *) &escontext);
 
-			if (SOFT_ERROR_OCCURRED(&escontext))
+			if (escontext.error_occurred)
 			{
 				errsave(parse->escontext,
 						errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
@@ -485,7 +485,7 @@ ndistinct_scalar(void *state, char *token, JsonTokenType tokentype)
 			 */
 			parse->ndistinct = pg_strtoint32_safe(token, (Node *) &escontext);
 
-			if (!SOFT_ERROR_OCCURRED(&escontext))
+			if (!escontext.error_occurred)
 			{
 				parse->state = NDIST_EXPECT_KEY;
 				return JSON_SUCCESS;