Remove superfluous newlines in function prototypes.

These were introduced by pgindent due to fixe to broken
indentation (c.f. 8255c7a5ee). Previously the mis-indentation of
function prototypes was creatively used to reduce indentation in a few
places.

As that formatting only exists in master and REL_12_STABLE, it seems
better to fix it in both, rather than having some odd indentation in
v12 that somebody might copy for future patches or such.

Author: Andres Freund
Discussion: https://postgr.es/m/20190728013754.jwcbe5nfyt3533vx@alap3.anarazel.de
Backpatch: 12-

src/include/replication/logical.h

@@ -17,8 +17,7 @@
 
 struct LogicalDecodingContext;
 
-typedef void (*LogicalOutputPluginWriterWrite) (
-												struct LogicalDecodingContext *lr,
+typedef void (*LogicalOutputPluginWriterWrite) (struct LogicalDecodingContext *lr,
 												XLogRecPtr Ptr,
 												TransactionId xid,
 												bool last_write
@@ -26,8 +25,7 @@ typedef void (*LogicalOutputPluginWriterWrite) (
 
 typedef LogicalOutputPluginWriterWrite LogicalOutputPluginWriterPrepareWrite;
 
-typedef void (*LogicalOutputPluginWriterUpdateProgress) (
-														 struct LogicalDecodingContext *lr,
+typedef void (*LogicalOutputPluginWriterUpdateProgress) (struct LogicalDecodingContext *lr,
 														 XLogRecPtr Ptr,
 														 TransactionId xid
 );
@@ -102,8 +100,7 @@ extern LogicalDecodingContext *CreateInitDecodingContext(char *plugin,
 														 LogicalOutputPluginWriterPrepareWrite prepare_write,
 														 LogicalOutputPluginWriterWrite do_write,
 														 LogicalOutputPluginWriterUpdateProgress update_progress);
-extern LogicalDecodingContext *CreateDecodingContext(
-													 XLogRecPtr start_lsn,
+extern LogicalDecodingContext *CreateDecodingContext(XLogRecPtr start_lsn,
 													 List *output_plugin_options,
 													 bool fast_forward,
 													 XLogPageReadCB read_page,