Remove HEADER_SEARCH_PATHS that search Frameworks in Xcode.app

Summary: In D33581989 (facebook@020cae8) we see that we don't need to search for any PrivateFrameworks, since these are linked at runtime and we have copies of these headers where appropriate. This means that this entire search can be removed.

Reviewed By: jamescoggan

Differential Revision: D33582097

fbshipit-source-id: dea1fbdb7b72b68d3dcd595670b80493152f0879

Configuration/Shared.xcconfig

@@ -51,7 +51,6 @@ GCC_WARN_UNUSED_VARIABLE = YES
 
 // Search Paths for Frameworks & Headers
 ALWAYS_SEARCH_USER_PATHS = NO
-FRAMEWORK_SEARCH_PATHS = $(inherited) $(DEVELOPER_LIBRARY_DIR)/PrivateFrameworks $(SDKROOT)/System/Library/PrivateFrameworks /Library/Developer/PrivateFrameworks
 HEADER_SEARCH_PATHS = $(inherited) $(SRCROOT)/PrivateHeaders
 
 // SDK & OS Versions