efi_selftest: cosmetic: fix spelling in comments

Fix a few UEFI function names, as well as a typo.

Signed-off-by: Vincent Stehlé <vincent.stehle@arm.com>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Cc: Tom Rini <trini@konsulko.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

lib/efi_selftest/efi_selftest_manageprotocols.c

@@ -6,7 +6,7 @@
  *
  * This unit test checks the following protocol services:
  * InstallProtocolInterface, UninstallProtocolInterface,
- * InstallMultipleProtocolsInterfaces, UninstallMultipleProtocolsInterfaces,
+ * InstallMultipleProtocolInterfaces, UninstallMultipleProtocolInterfaces,
  * HandleProtocol, ProtocolsPerHandle,
  * LocateHandle, LocateHandleBuffer.
  */
@@ -189,7 +189,7 @@ static int execute(void)
 	}
 
 	/*
-	 * Test error handling in UninstallMultipleProtocols
+	 * Test error handling in UninstallMultipleProtocolInterfaces
 	 *
 	 * These are the installed protocol interfaces on handle 2:
 	 *
@@ -240,7 +240,7 @@ static int execute(void)
 		efi_st_error("LocateHandleBuffer failed to locate new handle\n");
 		return EFI_ST_FAILURE;
 	}
-	/* Clear the buffer, we are reusing it it the next step. */
+	/* Clear the buffer, we are reusing it in the next step. */
 	boottime->set_mem(buffer, sizeof(efi_handle_t) * buffer_size, 0);
 
 	/*
@@ -289,7 +289,7 @@ static int execute(void)
 	}
 
 	/*
-	 * Test UninstallMultipleProtocols
+	 * Test UninstallMultipleProtocolInterfaces
 	 */
 	ret = boottime->uninstall_multiple_protocol_interfaces(
 						handle2,