Updates to .clang-format (pytorch#7683)

1) No longer compact namespaces (revert from pytorch#5127)
2) Don't break on return type for long function declarations

Author: pietern

.clang-format

@@ -37,7 +37,7 @@ BreakAfterJavaFieldAnnotations: false
 BreakStringLiterals: false
 ColumnLimit:     80
 CommentPragmas:  '^ IWYU pragma:'
-CompactNamespaces: true
+CompactNamespaces: false
 ConstructorInitializerAllOnOneLineOrOnePerLine: true
 ConstructorInitializerIndentWidth: 4
 ContinuationIndentWidth: 4
@@ -68,7 +68,7 @@ PenaltyBreakComment: 300
 PenaltyBreakFirstLessLess: 120
 PenaltyBreakString: 1000
 PenaltyExcessCharacter: 1000000
-PenaltyReturnTypeOnItsOwnLine: 200
+PenaltyReturnTypeOnItsOwnLine: 2000000
 PointerAlignment: Left
 ReflowComments:  true
 SortIncludes:    true