Fix comments

Some of these comments were copied and pasted without updating them,
some of them were duplicates.

src/backend/utils/mb/Unicode/UCS_to_EUC_CN.pl

@@ -49,10 +49,6 @@ while (<FILE>)
 }
 close(FILE);
 
-#
-# first, generate UTF8 --> EUC_CN table
-#
-
 $file = "utf8_to_euc_cn.map";
 open(FILE, "> $file") || die("cannot open $file");
 
@@ -77,7 +73,7 @@ print FILE "};\n";
 close(FILE);
 
 #
-# then generate EUC_JP --> UTF8 table
+# then generate EUC_CN --> UTF8 table
 #
 reset 'array';
 

src/backend/utils/mb/Unicode/UCS_to_EUC_JP.pl

@@ -130,10 +130,6 @@ while (<FILE>)
 }
 close(FILE);
 
-#
-# first, generate UTF8 --> EUC_JP table
-#
-
 $file = "utf8_to_euc_jp.map";
 open(FILE, "> $file") || die("cannot open $file");
 

src/backend/utils/mb/Unicode/UCS_to_EUC_KR.pl

@@ -49,10 +49,6 @@ while (<FILE>)
 }
 close(FILE);
 
-#
-# first, generate UTF8 --> EUC_KR table
-#
-
 $file = "utf8_to_euc_kr.map";
 open(FILE, "> $file") || die("cannot open $file");
 
@@ -77,7 +73,7 @@ print FILE "};\n";
 close(FILE);
 
 #
-# then generate EUC_JP --> UTF8 table
+# then generate EUC_KR --> UTF8 table
 #
 reset 'array';
 

src/backend/utils/mb/Unicode/UCS_to_EUC_TW.pl

@@ -65,10 +65,6 @@ while (<FILE>)
 }
 close(FILE);
 
-#
-# first, generate UTF8 --> EUC_TW table
-#
-
 $file = "utf8_to_euc_tw.map";
 open(FILE, "> $file") || die("cannot open $file");
 
@@ -93,7 +89,7 @@ print FILE "};\n";
 close(FILE);
 
 #
-# then generate EUC_JP --> UTF8 table
+# then generate EUC_TW --> UTF8 table
 #
 reset 'array';
 

src/backend/utils/mb/Unicode/UCS_to_SJIS.pl

@@ -66,10 +66,6 @@ while (<FILE>)
 
 close(FILE);
 
-#
-# first, generate UTF8 --> SJIS table
-#
-
 $file = "utf8_to_sjis.map";
 open(FILE, "> $file") || die("cannot open $file");