Fix misc typos and some cosmetic code cleanup (#12695)

pgxn/neon/file_cache.c

@@ -635,6 +635,11 @@ lfc_init(void)
 							NULL);
 }
 
+/*
+ * Dump a list of pages that are currently in the LFC
+ *
+ * This is used to get a snapshot that can be used to prewarm the LFC later.
+ */
 FileCacheState*
 lfc_get_state(size_t max_entries)
 {
@@ -2267,4 +2272,3 @@ get_prewarm_info(PG_FUNCTION_ARGS)
 
 	PG_RETURN_DATUM(HeapTupleGetDatum(heap_form_tuple(tupdesc, values, nulls)));
 }
-

pgxn/neon/neon.c

@@ -1,7 +1,7 @@
 /*-------------------------------------------------------------------------
  *
  * neon.c
- *	  Main entry point into the neon exension
+ *	  Main entry point into the neon extension
  *
  *-------------------------------------------------------------------------
  */
@@ -508,7 +508,7 @@ _PG_init(void)
 
 	DefineCustomBoolVariable(
 							"neon.disable_logical_replication_subscribers",
-							"Disables incomming logical replication",
+							"Disable incoming logical replication",
 							NULL,
 							&disable_logical_replication_subscribers,
 							false,
@@ -567,7 +567,7 @@ _PG_init(void)
 
 	DefineCustomEnumVariable(
 							"neon.debug_compare_local",
-							"Debug mode for compaing content of pages in prefetch ring/LFC/PS and local disk",
+							"Debug mode for comparing content of pages in prefetch ring/LFC/PS and local disk",
 							NULL,
 							&debug_compare_local,
 							DEBUG_COMPARE_LOCAL_NONE,
@@ -735,7 +735,6 @@ neon_shmem_request_hook(void)
 static void
 neon_shmem_startup_hook(void)
 {
-	/* Initialize */
 	if (prev_shmem_startup_hook)
 		prev_shmem_startup_hook();
 

pgxn/neon/relsize_cache.c

@@ -13,6 +13,7 @@
 #include "neon.h"
 #include "neon_pgversioncompat.h"
 
+#include "miscadmin.h"
 #include "pagestore_client.h"
 #include RELFILEINFO_HDR
 #include "storage/smgr.h"
@@ -23,10 +24,6 @@
 #include "utils/dynahash.h"
 #include "utils/guc.h"
 
-#if PG_VERSION_NUM >= 150000
-#include "miscadmin.h"
-#endif
-
 typedef struct
 {
 	NRelFileInfo rinfo;