Fix a linker error when compiling OpenEXR statically on Linux

Linking OpenEXR and IlmBase statically on Linux failed due to
interdependencies between Iex and IlmThread. Simply reversing their
order in CMakeLists.txt fixes the issue (which only arises on Linux
since the GNU linker is particularly sensitive to the order of static
libraries)

OpenEXR/IlmImf/CMakeLists.txt

@@ -8,8 +8,8 @@ ADD_EXECUTABLE ( b44ExpLogTable
 
 TARGET_LINK_LIBRARIES ( b44ExpLogTable
   Half
-  Iex${ILMBASE_LIBSUFFIX}
   IlmThread${ILMBASE_LIBSUFFIX}
+  Iex${ILMBASE_LIBSUFFIX}
   ${PTHREAD_LIB}
 )
 
@@ -25,8 +25,8 @@ ADD_EXECUTABLE ( dwaLookups
 
 TARGET_LINK_LIBRARIES ( dwaLookups
   Half
-  Iex${ILMBASE_LIBSUFFIX}
   IlmThread${ILMBASE_LIBSUFFIX}
+  Iex${ILMBASE_LIBSUFFIX}
   ${PTHREAD_LIB}
 )