Fix typo in bld.bat files

Author: ndgrigorian

conda-recipe-cf/bld.bat

@@ -16,6 +16,6 @@ set "CC=icx"
 set "CMAKE_GENERATOR=Ninja"
 set "VERBOSE=1"
 
-set MKLROOT=%PREFIX%
+set "MKLROOT=%PREFIX%"
 %PYTHON% -m pip install --no-build-isolation --no-deps .
 if errorlevel 1 exit 1

conda-recipe/bld.bat

@@ -16,6 +16,6 @@ set "CC=icx"
 set "CMAKE_GENERATOR=Ninja"
 set "VERBOSE=1"
 
-set MKLROOT=%PREFIX%
+set "MKLROOT=%PREFIX%"
 %PYTHON% -m pip install --no-build-isolation --no-deps .
 if errorlevel 1 exit 1