Fixed the bug in PR to pass UTs

Signed-off-by: Athish Pranav D <[email protected]>

lib/fluent/config/literal_parser.rb

@@ -155,11 +155,11 @@ def scan_nonquoted_string(boundary_charset = LINE_END)
       end
 
       def scan_embedded_code
-        src = '#{'+@ss.rest+"\n=begin\n=end\n}"
+        src = '"#{'+@ss.rest+"\n=begin\n=end\n}"
 
         seek = -1
         while (seek = src.index('}', seek + 1))
-          unless Ripper.sexp(src[0..seek]).nil? # eager parsing until valid expression
+          unless Ripper.sexp(src[0..seek] + '"').nil? # eager parsing until valid expression
             break
           end
         end
@@ -168,14 +168,15 @@ def scan_embedded_code
           raise Fluent::ConfigParseError, @ss.rest
         end
 
-        code = src[2, seek-2]
+        code = src[3, seek-3]
 
         if @ss.rest.length < code.length
           @ss.pos += @ss.rest.length
           parse_error! "expected end of embedded code but $end"
         end
 
         @ss.pos += code.length
+
         '"#{' + code + '}"'
       end