[docs] Use dbgs() instead of errs() for DEBUG()

The examples in llvm/Support/Debug.h use `DEBUG(dbgs() << ...)` instead
of `errs()`, so the examples in the Programmer's Manual should match
that.

Patch by: Moritz Sichert <moritz.sichert@googlemail.com>

Differential revision: https://reviews.llvm.org/D41170

llvm-svn: 321444
diff --git a/llvm/docs/ProgrammersManual.rst b/llvm/docs/ProgrammersManual.rst
index 719d399..07048a5 100644
--- a/llvm/docs/ProgrammersManual.rst
+++ b/llvm/docs/ProgrammersManual.rst
@@ -1040,7 +1040,7 @@
 
 .. code-block:: c++
 
-  DEBUG(errs() << "I am here!\n");
+  DEBUG(dbgs() << "I am here!\n");
 
 Then you can run your pass like this:
 
@@ -1076,10 +1076,10 @@
 .. code-block:: c++
 
   #define DEBUG_TYPE "foo"
-  DEBUG(errs() << "'foo' debug type\n");
+  DEBUG(dbgs() << "'foo' debug type\n");
   #undef  DEBUG_TYPE
   #define DEBUG_TYPE "bar"
-  DEBUG(errs() << "'bar' debug type\n"));
+  DEBUG(dbgs() << "'bar' debug type\n");
   #undef  DEBUG_TYPE
 
 Then you can run your pass like this:
@@ -1120,8 +1120,8 @@
 
 .. code-block:: c++
 
-  DEBUG_WITH_TYPE("foo", errs() << "'foo' debug type\n");
-  DEBUG_WITH_TYPE("bar", errs() << "'bar' debug type\n"));
+  DEBUG_WITH_TYPE("foo", dbgs() << "'foo' debug type\n");
+  DEBUG_WITH_TYPE("bar", dbgs() << "'bar' debug type\n");
 
 .. _Statistic: