Correct doc errors

Author: mendell27

sycl/doc/extensions/supported/sycl_ext_intel_fpga_device_selector.asciidoc

@@ -42,8 +42,6 @@ SYCL specification refer to that revision.
 
 == Status
 
-_Use this if the extension becomes "supported":_
-
 This extension is implemented and fully supported by {dpcpp}.
 
 [NOTE]
@@ -119,8 +117,8 @@ has multiple versions._
 == Implementation notes
 
 The current implementation has a restriction on the use of
-+{fpga_simulator_selector}+.  If an object of +{fpga_simulator_selector}+ is
+`fpga_simulator_selector`.  If an object of `fpga_simulator_selector` is
 defined in the application, FPGA hardware devices selected using
-+{fpga_selector}+ will select a simulator device. This behaviour is expected to
+`fpga_selector` will select a simulator device. This behaviour is expected to
 be eliminated in the future.